Thousands of residents in the San Juan islands northwest of Seattle have been operating without phone or Internet service for a week after an underwater cable was mysteriously severed. Now, more information is coming to light about the cause of the problem.

CenturyLink says it has identified both ends of the severed cable, which had been located at a water depth of 280 feet about 5,000 feet from Lopez Island. The cut also impacted wireless service to the islands, provided by AT&T and Verizon.

Severed cable from the San Juan islands. Photo via KOMO News.

“The cause for movement (in the cable) is unknown, but could have been caused by an earthquake that occurred three minutes prior to CenturyLink’s first alarm notification,” the company said in a press release.

CenturyLink is now assessing the damage in the cable, and moving a barge into place to anchor the suspended cable.

Once in place, technicians will splice the new fiber to the severed lines and identify where to secure the new cable.

“Typically a response effort of this magnitude takes over a month to develop; the fact that we were able to mobilize within the first 36 hours is amazing. Restoring service is a top priority for CenturyLink, and we have pulled resources in from across the country to get these facilities up and running,” said Tim Grigar, vice president and general manager of CenturyLink’s western Washington market.

The lack of Internet and phone service has led San Juan County to declare a state of emergency. It was like “some post-apocalyptic scene of people standing around with laptops, hungry for internets,” one person who was there told us last week.

CenturyLink was able to institute a temporary fix to restore local, long distance and 911 phone service on the islands, but issues with Internet connectivity still remain.

Here’s a report on the situation from our news partners at KING 5, which notes that some of the tourist-oriented businesses in the islands are losing out on sales due to the Internet outage.

John Cook is GeekWire's co-founder and publisher, a veteran reporter and the longest-serving journalist on the Pacific Northwest tech beat. Follow him @johnhcook and email john@geekwire.com.